Background: Older adults exhibit more fragmented circadian rhythm as they age, and undergo age-related changes in sleep patterns that influence sleep duration, timing, and overall satisfaction. Several challenges exist in conducting inclusive research for promoting healthy sleep and aging over the lifespan. Multiple sleep dimensions exist and complicate synthesis of sleep findings. Sleep health disparities also disproportionately affect the same populations that experience overall health disparities, yet diverse groups are underrepresented. Methods: Study 1 examined prospective associations between self-reported sleep from the Hispanic Community Health Study / Study of Latinos (n=10,640) and actigraphy-derived sleep/circadian measures from Sueño (n=1,808) with multimorbidity at follow-up. Study 2 used an ensemble of machine learning techniques to identify accelerometry-derived sleep and circadian profiles; we then examined associations between sleep-circadian profiles, fall risk, and physical functioning among 4,543 diverse older women in OPACH. Study 3 linked accelerometry data, claims, and genetic data to construct two network models to simultaneously evaluate the relationship between multiple sleep rest-activity rhythm measures with each cognitive outcome (e.g., dementia and Alzheimer’s Disease).
Results: In study 1, several sleep and circadian measures were associated with comorbidity at follow-up, and we observed effect modification of these associations by US-born and non-US-born status and duration of residency. In study 2, we identified multiple sleep and circadian profiles using machine learning, and these profiles were associated with greater fall risk and lower physical functioning. In study 3, several circadian measures were indirectly associated with dementia and AD and shared a central hub in the network model. Results from adjusted survival models showed consistent associations with the network model.
Conclusion: This analysis enhances the field of life course epidemiology and sleep disparities research, having identified sleep and circadian behaviors as risk factors for disease and worse aging at middle and older ages. This study also highlights study designs that promote inclusive research when performing epidemiological studies on sleep
